eth_feeHistory RPC Method

The eth_feeHistory method provides historical gas fee stats over a range of recent blocks on the Base Mainnet.
It’s especially useful for fee estimation and analyzing how the network’s base fee and priority fees change over time.

✅ Great for building gas estimators
✅ Helps track congestion and baseFee trends

🔧 Parameters

blockCount (required)

Number of blocks in the requested range — can be a string or integer.
🔹 Must be between 1 and 1024.

newestBlock (required)

The highest block in the range.
Use a block number or one of the tags: "latest", "pending", "earliest".

View block tag documentation (opens in a new tab)

rewardPercentiles (optional)

A list of percentiles (e.g. [20, 50, 95]) used to sample effective priority fees per gas from each block.
Percentiles must be:

• Monotonically increasing
• Integers between 0 and 100

📥 Returns

• oldestBlock — The block number at the start of the range (hex)
• baseFeePerGas — Array of base fees for each block + 1 future block
• gasUsedRatio — Ratio of gas used per block (0–1 float)
• reward (if rewardPercentiles provided) — Arrays of effective priority fees per block. Empty blocks return zeroes.

📤 Request

POST https://base-mainnet.chainnodes.org/YOUR-API-KEY

✅ Replace YOUR-API-KEY with your API key from the CHAINNODES Dashboard (opens in a new tab).
✅ You can substitute base-mainnet with another supported network if needed.

📦 Example

curl https://base-mainnet.chainnodes.org/YOUR-API-KEY \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc":"2.0",
    "method":"eth_feeHistory",
    "params": ["0x8", "earliest", [20,25]],
    "id":1
  }'

📘 Response

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "oldestBlock": "0x0",
    "reward": [
      [
        "0x0",
        "0x0"
      ]
    ],
    "baseFeePerGas": [
      "0x0",
      "0x0"
    ],
    "gasUsedRatio": [
      0
    ]
  }
}